(a) Field of the Invention
The present invention relates to a wire structure, a thin film transistor array panel having the wire structure, and a manufacturing method of the same.
(b) Description of the Related Art
Generally, a thin film transistor array (“TFT”) panel for a liquid crystal display (“LCD”) or an electro-luminescence (“EL”) display is used as a circuit board for driving the respective pixels in an independent manner. The TFT array panel includes a scanning signal wire or a gate wire transmitting scanning signals, an image signal wire or a data wire transmitting image signals, TFTs connected to the gate and the data wire, pixel electrodes connected to the TFTs, a gate insulating layer covering the gate wire for insulation, and a passivation layer covering the TFTs and the data wire for insulation. The TFT includes a gate electrode, which is a part of the gate wire, a semiconductor layer forming a channel, source and drain electrodes, which are parts of the data wire, a gate insulating layer, and a passivation layer. The TFT is a switching element for transmitting the image signals from the data wire to the pixel electrode in response to the scanning signals from the gate wire.
The TFT array panel has been extensively used for the LCD. An LCD uses separate light sources. Especially, a transmitting type LCD and a trans-reflection type LCD have pixel electrodes made of transmittable conductive material such as indium tin oxide (ITO) and indium zinc oxide (IZO).
Both of ITO and IZO have demerits.
ITO needs strong acid as an etchant. Strong etchant can smear through pinholes of insulating layer and corrode data or gate wires.
IZO does not induce such a problem but is easily scribed by a test probe and stick to it. This feature of IZO disturb gross test which is done before mounting driving IC by increasing contact resistance of the test probe.